If you want your kit to transform, you'll want the MG of whichever RX-0 unit you fancy. However, they're obviously a lot more expensive and more complicated to build so if you want to try your techniques out on a starter kit first, you might want to consider picking up one of the 'Destroy Mode' HGUCs so you can play around with the psychoframe, then move up. Depends on your comfort level.

To get your own psychoframe colors, you can paint the existing parts with a metallic undercoat (usually silver) and then apply a clear color on top of it to get the look you want.

The PG is incredible. The wrists and shoulder joints aren't great, but everything else is NAILED. Best transformation you'll find, too - smooth, stable, well-designed - and probably the most show-accurate proportions too. Really good kit.

I dunno if I'd say the MG is "rubbish", but it's definitely showing its age a bit. I don't have any of the GFFMCs, but they're pretty pricey, possible more than even a PG. Almost certainly high quality, though, if my GFFMC RX-78 ORIGIN is anything to go by.

"The beast of opportunity finds its master and soars through a shaken cosmos"